Inverted Opal Fluorescent Film Chemosensor for the Detection of Explosive Nitroaromatic Vapors through Fluorescence Resonance Energy Transfer |
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Authors: | Qunling Fang Junlong Geng Bianhua Liu Daming Gao Dr Fei Li Zhenyang Wang Dr Guijian Guan Dr Zhongping Zhang Prof |
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Institution: | 1. Institute of Intelligent Machines, Chinese Academy of Sciences, P. O. Box 1130, 230031 (P.R. China), Fax: (+86)?551‐5591156;2. Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (P.R. China);3. Department of Chemistry & Materials Engineering, Hefei University. Hefei, Anhui 230022 (P.R. China) |
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Abstract: | This paper reports an inverted opal fluorescence chemosensor for the ultrasensitive detection of explosive nitroaromatic vapors through resonance‐energy‐transfer‐amplified fluorescence quenching. The inverted opal silica film with amino ligands was first fabricated by the acid–base interaction between 3‐aminopropyltriethoxysilane and surface sulfonic groups on polystyrene microsphere templates. The fluorescent dye was then chemically anchored onto the interconnected porous surface to form a hybrid monolayer of amino ligands and dye molecules. The amino ligands can efficiently capture vapor molecules of nitroaromatics such as 2,4,6‐trinitrotoluene (TNT) through the charge‐transfer complexing interaction between electron‐rich amino ligands and electron‐deficient aromatic rings. Meanwhile, the resultant TNT–amine complexes can strongly suppress the fluorescence emission of the chosen dye by the fluorescent resonance energy transfer (FRET) from the dye donor to the irradiative TNT–amino acceptor through intermolecular polar–polar resonance at spatial proximity. The quenching response of the highly ordered porous films with TNT is greatly amplified by at least 10‐fold that of the amorphous silica films, due to the interconnected porous structure and large surface‐to‐volume ratio. The inverted opal film with a stable fluorescence brightness and strong analyte affinity has lead to an ultrasensitive detection of several ppb of TNT vapor in air. |
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Keywords: | FRET inverted opal film nitrogen heterocycles sensors surface chemistry |
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